This invention relates to an efficiently operable modular system of clean benches which can be connected together in series such that objects on which various tasks are to be performed can be transported therethrough and the tasks can be carried out robotically within a clean-room environment.
A so-called clean room is commonly used for many production processes where a dust-free environment is essential, or at least highly desirable. A clean room is a sealed chamber into which clean air is constantly introduced and in which workers are normally required to wear a special dust-free outer garment. A clean room is generally large and is therefore relatively expensive to operate and to maintain in a dust-free condition. Since the air which has been circulated once is discharged out of the room and new supplies of external air are constantly being introduced, air filters become clogged quickly and must be exchanged frequently, and this also affects the operating cost of a clean room adversely. In addition, the protective garments required inside a clean room are generally uncomfortable to wear and tend to dishevel the wearer's hair.
In view of the above, so-called clean benches are sometimes substituted for use especially where the required space is not large. A typical prior art clean bench may be described as an ordinary work bench with an overhead outlet for filtered air such that a downward flow of clean air is established within a work space above the bench. With a clean bench thus formed, a worker is not required to wear any protective garment. Since such a clean bench does not provide any sealed enclosure, however, it can be useful only if the requirement for a dust-free environment is not so stringent. Since the downwardly circulated air is discharged thereafter and new supplies of external air must be introduced, the filters must still be exchanged frequently, although to a lesser degree because benches are much smaller than a room.